This invention relates to an apparatus for plugging the taphole of a shaft furnace. More particularly, this invention relates to an apparatus comprised of a fixed support frame having a main pivot and a jib. The jib consists of a rotary support arm which is rotatably mounted via a first end to the main pivot joint. The second end of the rotary support arm is pivotably mounted via an auxiliary pivot to a clay gun. A guide bar is pivotably connected at one end to the clay gun and at the other end to the fixed frame. The apparatus disclosed herein also has a hydraulic jack which is mounted on journals in the fixed support frame. The jack has a piston rod which accurates the support arm, thereby causing the support arm and the clay gun to alternately pivot from a retracted position to an operative position.
Taphole plugging devices of this type are described in French Pat. No. A 71 42 470 and are well known to those skilled in the art. Conventional devices of the type herein described have been in worldwide use for over ten years. During this time period, conventional plugging devices have undergone many changes and improvements, particularly for the purpose of improving and providing a satisfactory trajectory for the clay gun and for reducing the space which the clay gun occupies in the vertical direction. The most important improvements in conventional plugging devices have been made in connection with the angles of inclination of the main pivot and the auxiliary pivot, both in respect to each other and in respect to the vertical axis.
While the height of the plugging apparatii have been improved in recent years, problems still exist in regard to the overall area occupied by these devices. It is well known that the hydraulic jack used in connection with known plugging devices act on a support arm which is positioned in close proximity to a main pivot joint. The journals of the hydraulic jack therefore, must be positioned at a a relatively large distance away from the main pivot joint thereby necessitating a comparatively large frame. Moreover, the cylinder of the jack used in known plugging devices usually extends a considerable length beyond this large frame. As a result, the cylinder forms an obstruction over both the entire length of the plugging device as well as the surface swept out by the cylinder (since the cylinder pivots about the journals of the jack during the operation of the clay gun).
Another problem associated with known taphole plugging devices is that when the clay gun is in its retracted position, access to the clay gun by an operator is impeded from the side opposite that of the furnace. This lack of access to the clay gun in its retracted position is troublesome and undesirable from the standpoint of operational efficiency.